Vacancies in the United States Senate


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Unlike vacancies in the U.S. House of Representatives, which are required by law to be filled by elections, the U.S. Constitution allows states to choose how to fill vacancies in the U.S. Senate. All states do so through elections, but they vary in two ways: whether the vacancy is filled at a regularly scheduled election or at a special election; and whether the governor can make an appointment to fill the vacancy during the period before the election occurs.

Presently, 37 states fill Senate vacancies at their next regularly scheduled general election. The remaining 13 require that a special election be called. And only four states prohibit the governor from making an interim appointment, requiring instead that the seat remain vacant until the next election (whether regular or special) is held. In another three, the governor may make an appointment to fill the vacancy temporarily, but only under very strict conditions.

Vacancies Filled by Gubernatorial Appointment

In the following 37 states, the governor makes an appointment to fill a U.S. Senate vacancy, and the appointee serves until the next regularly scheduled, statewide general election. The person elected in that general election serves for the remainder of the unexpired term, if any. If the term was set to expire at that general election, the person elected serves a full six-year term.



New York (2)



North Carolina (1)

Arizona (1)




Maryland (1)




South Carolina


Minnesota (2)

South Dakota






Utah (1)

Hawaii (1, 2, 3)


Virginia (2)



West Virginia


New Hampshire

Wyoming (1)


New Jersey (2)



New Mexico



(1) The governor’s appointee must be of the same political party as that of the vacating senator.

(2) If the vacancy occurs before a specified date preceding the regular primary (Hawaii, 21 days; Minn., 11 weeks; N.J., 30 days; N.Y., 59 days; Va., 120 days), the election is held the following November; if the vacancy occurs within the specified period preceding the regular primary, the vacancy election is held at the second November election after the vacancy occurs.

(3) The governor makes an appointment by selecting from a list of three prospective appointees submitted by the party.

Vacancies Filled by Special Election

In contrast to the states above, the 14 states listed below require that a special election be held to fill a vacancy in the office of U.S. Senator. 

Interim Gubernatorial Appointment?
When Must the Special Election be Held?


​Alaska Stat. 15.40.140, 15.140.142, 15.10.145


A special election must be held 60-90 days after vacancy occurs. If the vacancy occurs 60-90 days before the primary election, the special election shall be held on the date of the primary election.


C.G.S.A. 9-211


160th day after vacancy occurs (excluding weekends), unless vacancy occurs between the 125th and 63rd days preceding a regularly scheduled November general election, in which case vacancy is filled at that election. Governor may make a temporary appointment only in cases where a vacancy occurs after the municipal election in the year preceding the last year of the term or in the last year of the term of a senator. Approval of such nomination requires an affirmative vote of two-thirds of the membership of each chamber of the General Assembly.


LSA-R.S. 18:402, 18:1278


On specific dates provided by law. If the unexpired term is more than one year, an appointment to fill the vacancy shall be temporary. Any senator so appointed shall serve until his successor is elected at a special election and takes office. If the unexpired term is one year or less, no special election is called but the successor is chosen at the next regular election.


M.G.L.A. 54 §140


145-160 days after vacancy occurs. If a vacancy occurs after April 10 but on or before the 70th day before the regular state primary, the office shall appear on the regular state primary ballot. If a vacancy occurs after that time, the office shall appear on the state election ballot that November.


Miss. Code Ann. 23-15-855


Within 100 days of when governor receives official notice of vacancy, unless vacancy occurs in the year of a general state or congressional election, in which case the vacancy is filled in that election

North Dakota

NDCC 16.1-13-08


When a vacancy occurs in the office of United States senator from this state, the governor shall call a special election to be held within 95 days to fill the vacancy. If the vacancy occurs within 95 days of the expiration of the term of office for that office, no election may be held to fill the vacancy.


​26 Okl. Stat. Ann. 12-101


Within 30 days after the vacancy occurrs. No special election is held if the vacancy occurs in an even-numbered year and the term expires the following year. In that case, the candidate is elected in the regular general election.


O.R.S. 188.120


A special election is called by the governor if the vacancy occurs before the 61st day before a general election.

Rhode Island

​Gen. Laws 17-4-9


At as early a date as is in compliance with the provisions of law. If vacancy occurs between July 1 and Oct. 1 in an even-numbered year, the special election to fill the vacancy is held concurrently with the regularly scheduled general election.


​V.T.C.A. Election Code 204.002, 204.005


If vacancy occurs in an even year on or before the 62nd day before the primary, remainder of term is filled at next regular general election. If vacancy occurs after 62nd day before the primary in an even year, or in an odd year, special election is held on the first uniform election date occurring on or after the 36th day the election is ordered.


​17 V.S.A. 2621


A date is set by the governor within six months following vacancy, unless vacancy occurs within six months of the general election, in which case the vacancy is filled at the general election.


​RCWA 29A.28.030, 29A.28.041


Not less than 80 days following vacancy, unless vacancy occurs within eight months of the general election, in which case the vacancy is filled at the general election


W.S.A. 17.18, 8.50


Between 62 and 77 days after date of order of special election, unless vacancy occurs between the second Tuesday in May and the second Tuesday in July in an even year, in which case the vacancy is filled at the regular primary and general elections

Recent Legislative Action

  • In 2019, Vermont amended the timeline for calling a special election. Three other states considered but did not pass legislation relating to U.S. Senate vacancies.
  • In 2018, Alabama adopted SB 15, which ends special elections to fill vacancies. Instead, the bill allows the governor to fill a vacancy by appointment and prohibits a person appointed to fill the vacancy from running for election to the office for the next full term of office.
  • In 2017, Arkansas enacted HB 1279, which gives the governor the responsibility to appoint the replacement.
  • In 2016, Maryland enacted HB 260, which requires the individual appointed by the governor to fill the vacancy to be of the same political party of the vacating senator.
  • In 2015, North Dakota enacted HB 1181, which requires a special election and removes the power of the governor to appoint a replacement. Hawaii enacted SB 440 which made changes to the timeline of when an election to fill a vacancy is held. If a vacancy occurs not later than the 21st day, rather than the 60th day, before the close of filing nomination papers for regularly scheduled elections, the vacancy is filled at the following state general election.
  • In 2012, five states considered but did not pass legislation dealing with U.S. Senate vacancies.
  • In 2011, three states considered but did not pass legislation dealing with U.S. Senate vacancies.
  • In 2010, seven states considered legislation to change the way vacancies in the U.S. Senate are filled; none of that legislation passed.
  • In 2009, 12 of the states that currently permit the governor to fill U.S. Senate vacancies by appointment considered legislation to take away that authority and require a special election instead.  Connecticut and Rhode Island passed legislation along these lines; in Colorado, Maryland, Missouri, and North Carolina,  the bills failed to pass. In Illinois, Iowa, Minnesota, New York, Ohio and Pennsylvania, the bills carried over to the 2010 legislative sessions.  In Massachusetts a bill was passed in response to the death of Senator Edward Kennedy and his request that the current law be changed. Previous law in Massachusetts called for a special election to be held, but not until five months after the vacancy occurs. The new law retains the special election, but permits the governor to appoint a temporary successor in the interim.
  • In 2008, bills addressing U.S. Senate vacancies were introduced but failed to pass in Massachusetts, Minnesota and Rhode Island. In Kansas, the legislature passed a bill removing the governor's authority to make an appointment to fill a vacancy in the office of U.S. Senator, but it was vetoed by the governor.

Federal Laws

Article I of the U.S. Constitution, amended by the 17th Amendment, and one section of the U.S. Code relate directly to how states may fill vacancies in the U.S. Senate.

U.S. Constitution, Article I, Section 3

“...if vacancies happen by resignation, or otherwise, during the recess of the legislature of any state, the executive thereof may make temporary appointments until the next meeting of the legislature, which shall then fill such vacancies.”

U.S. Constitution, 17th Amendment

“When vacancies happen in the representation of any state in the Senate, the executive authority of such state shall issue writs of election to fill such vacancies: Provided, that the legislature of any state may empower the executive thereof to make temporary appointments until the people fill the vacancies by election as the legislature may direct.”

2 U.S.C. Section 8. Vacancies

“The time for holding elections in any State, district, or territory for a Representative or Delegate to fill a vacancy, whether such vacancy is caused by a failure to elect at the time prescribed by law, or by the death, resignation, or incapacity of a person elected, may be prescribed by the laws of the several States and territories respectively.”

Additional NCSL Resources